Heat-absorbing water conduit for tank water heaters



[2,371,346- HEATERS I March 13, 1945. c, H-.' MORROW ABSORBING WATER c NDUITs FQR TANK WATER Filed May 11, 1942 INVENTOR CLARJENCE, H. MORROW' ATTORNEYS Patented Mar. 13, 1945 HEAT-ABSORBING WATER CONDUIT FOR TANK WATER HEATERS Clarence H. Morrow, Shaker Heights, Ohio, assignor to The Hotstream Heater Company, Cleveland, Ohio, a corporation of Ohio Application May 11, 1942, Serial No. 442,532

c Claims. (01. 257- 248) This invention relates to improvements inthe heat-absorbing water conduits of tank water heaters, such as are used-in conjunction with storage tanks or. reservoirs for the heating of the water thereof, the conduits of said tank heaters'being connected in circulatory communication with said storage tanks or reservoirs and being subjected, for heat-absorbing purposes, to the hot combustion gases produced by the burners of said tank heaters.

The present invention has for its principal object the'provision of a novel and improved tank heater water conduit which is in the form of a simple and inexpensive casting of metal now readily available, such as cast iron, and which conduit is particularly well adapted for efiicient and rapid heat absorption.

A further object of the present invention is the provision of a novel and improved tank heater water conduit which is provided with heat-absorbing fins so constructed and arranged as to insure such intimate and prolonged contact of the hot combustion gases with the conduit and its fins as to enable a maximum amount of heat to be transferred from such gases to the water in said conduit.

A further object of the present invention is the provision of a novel and improved tank heat er water conduit which is of such character that the tank heater casing structure may be read- .ily supported thereon, thus making unnecessary the use of the' fastening devices heretofore employed for the mounting of a tank heater water conduit in the enclosing casing therefor, etc.

many of its practical advantages, willbe referred to in or will be evident from the following description of one embodiment of such invention, reference being had to the accompanying drawing, in which Fig. l is a central vertical sectional view of a tank water heater containing a water conduit embodying the present invention, the conduit appearing in side elevation;

cific arrangement of parts herein illustrated or described, as the invention obviously may take other forms. It also is to be understood that the terminology or phraseology herein employed is for the purpose of description and not of limitation, the scope of the present invention being indicated by the appended claims.

As will be evident from the accompanying drawing, the tank heater water conduit l0 here illustrated, for the disclosure of the present invention, consists of a simple and inexpensive oneiece casting, the casting being of metal now readily available; such as cast iron. As best shown in Fig. 1, the conduit III is of generally rectangular form in side elevation, and from Fig. 2, it will be evident that said conduit is of generally oval shape in cross-section. At the bottom of said conduit is a rearward extension II of tubular form which constitutes the water inlet portion of the conduit, and at the top of said conduit is an upright extension I! of tubular form which constitutes the water outlet portion thereof, said outlet extension being here shown (see Fig. 1) as offset rearwardly somewhat, for reasons which will hereinafter appear.

For heat-absorbing purposes and for directing and controlling the fiow of the hot combustion gases therealong, the conduit I0 is provided on each of its two curved side walls with three longitudinally spaced sets of integral fins, the fins of each such set being laterally -spaced, generally parallel and longitudinally disposed, with the fins of the three sets in alignment, as here shown.

- Although each such set here contains the same Further objects of the present invention, and

Fig. 2 is a cross-sectional view of said tank 5 heater and its water conduit, the view being on 'the line 2-2, Fig. 1; and

Figs. 3 to 6 inclusive are respectively a rear elevational view, a front elevational view, a top plan view and -a bottom plan view of said water ,50

conduit.

Before the tank heater water conduit here illustrated is specifically described, it is to be understood that the invention here involved is not limited to the details of construction or the spe- 15 of said conduit-the portion lying above the number of fins, there being. nine fins in each set, it is obvious that the number of fins which each set contains may vary as desired. It' is preferable, however, to have the. fins of each set in l3 on one side of the conduit may extend down around the bottom of the conduit and merge with the bottom fins IS on the other side of the conduit (see Figs. 1 and 6). It'also is desirable that the top fins II on each side of the conduit terminate below the conduit top wall for reasons which will" hereinafter appear, the top portion The being designated by the reference numeral i8.

As best shown in Figs. 3 and 4, the two fins of each such front and rear set are longitudinally spaced and extend from opposite sides of the conduit at least to the longitudinal 'center line thereof. Preferably, the front and rear fins are respectively joined at their outer ends with the adjacent side wall fins, as will be evident from Figs. 1, 5 and 6. Although. they need not be, the front and rear fins are in corresponding alignment, the front fins H and the rear fins I3 of the two lower sets being located slightly above transverse side wall channels 20, which space or separate the bottom' side wall fins l3 from the intermediate side wall fins 2|, and the front fins II and the rear fins if! of the two upper sets being located just above transverse.

side wall channels 22 and 23 which space or separate the intermediate side wall fins 2| from the top side wall fins l4. As best shown in Figs. 3

and 4, the two lower side wall channels are in alignment, and as a. result the bottom fins l3 oneach side of the conduit are of equal length. The two upper side wall channels 22 and 23,

however, are out of alignment, the channel22 on the right side of the conduit (as viewed from the front thereof) being somewhat higher than the corresponding channel 23. As a result, the top fins M on the right side of the conduit have a somewhat shorter length than the corresponding tins I 4 on the left side of the conduit, as clearly shown in Figs. 3 and 4.

As best shown in Figs. 2, 5 and 6, the side wall fins l3, l3 and 2| are of varying depth, the fins beingof progressively decreasing depth toward the front and rear of the conduit to preserve its generally oval cross-sectional shape. For the trallv disposed aperture of the jacket bottom cap 21. For ailording access to said burner, the jacket 25 and the combustion chamber shell 23 are provided with registering side wall openings which are normally closed by a hinged door 32 with which the jacket is provided.

Suitably mounted on the upper end of the combustion chamber shell 29, and providing an upright flue passageway for the hot combustion gases produced by the burner 3|, is a tubular shell 33, said shell being of oval-shaped crosssection, as clearly shown in Fig. 2. Suitably mounted on the upper end of this oval-shaped shell 33 is a ring member having an annular peripheral flange 33 which extends upwardly into engagement with the jacket top cap 26 and which laterally defines a cylindrical header or collecting chamber 35 in communication with the flue pasoutlet being surrounded, as is usual, by an upright annular flange 35 for connection to a stack or chimney (not shown).

Asbest shown in Fig. l, the conduit Ill is arranged in upright position in the combustion chamber 30 and the oval-shaped flue passageway leading therefrom. In the jacket top cap 26 is a suitable aperture 37 'for the reception. of the upright outlet extension I 2 of the, conduit l3, and in the rear portion of the cylindrical combustion chamber shell-23 is a suitable aperture 38 for. the reception of the rearwardly projecting inlet extension ll of said conduit. If desired, said inlet extension may have cast thereon same purpose, the transversely disposed front and rear fins i1 and I8 have rounded free edges,

-as will be evident from Figs. 2, 5 and 6.

As will be readily understood, water conduits embodying the present invention may be used in tank heaters having enclosingcasing structures of various forms. Merely for purposes of illustration, therefore, Figs. 1 and, 2 show the present water conduit as used in a tank heater having a casing of the form disclosed in my co-pending application for Casings for water heaters, Serial No. 435,757, filed March 23, 1942, to which application reference may be had, if desired. So far as description of such casing is here necessary, it may be stated that said casing comprises an outer cylindrical jacket 25 having circular top and bottom caps 26 and 21, 'respec-' tlvely, the bottom cap 21 being provided with suitable air openings 28. Supported on said bottom cap 2Lin'spaoed relation to the cylindrical side wall of the jacket 25, is. a generally cylindrical shell 29 which laterally defines a combustion chamber 30, the air inlet openings 23 being in communication with said chamber. as-shown in Fig. 1. Located within said combustion chamber is; suitable gas burner 3| mounted on the upper end of a gas and air mixing tube 32, said mixing tube being suitably-mounted in a cenextending inwardly through the jacket side wall and the combustion chamber shell 29, and by suitably tightening the nut on the inner end of said bolt, a rigid connection of the tank heater casing to the conduit Ill can be easily and convenierltly I efiected. Although the oval-shaped conduit 13 fits more or less snugly within the correspondingly shaped flue passageway of the upright shell 33, as clearly shown in Fig. 2, and there is thus no necessity for providing at the top of the conduit additional means for preventing said conduit from turning about its longitudinal' axis, the upright outlet extension l2 of said conduit may be provided, if desired, with lateral projections 43 and the jacket top cap aperture 31 provided with corresponding extensions to receive said projections, as will be readily understood. i

In use of the present tank heater with a water storage tank or reservoir (not shown), for the heating of the water thereoLthe conduit ll'of said tank heater is connected in circulatory com-' munication withsaid storage tank or'reservoir. In other words, the conduit inlet extension II is connected to a suitable supply pipe (not shown) leading from the storage tank or reservoir, the jacket side wall being provided with a suitable aperture 34 to receive said pipe, and the outlet extension I 2 of said conduit is connected to a suitablereturn pipe (not shown) leading to said storage tank or reservoir. For the connection of the conduit inlet and outlet extensions to such pipes, any suitable meanslmay be used, the conduit extensions being here internally threaded for simple and convenient connection to ex-' Due to the rearwardly which connects the flange 36 to the stack or chimney.

As best shown in Fig. 1, thetransverse lower side wall channels of the conduit l0 (formed by interrupting the side wall fins I 3 and 2|). lie

. just below the entrance to the oval-shaped fiue p ssageway. When the hot combustion gases produced by the burner 3| first enter the vertically disposed and relatively narrow passages provided by the bottom side wall fins l3, they travel along'the bases of said passages and hence are in intimate contact with the side walls or primary heat-absorbing surface of the condui t.

The gases have a tendency, however, to move outwardly from the conduit walls, and the function of the lower transverse channels 20, into which the gases fiow from the bottom fin passages 45, is to direct the now unobstructed gases into the oval-shaped fiue passageway with the desired velocity and with the desired distribu tion across the conduit side walls. In travelling upwardly through the relatively narrow passages 46 provided by the intermediate side wall fins be evident that the present conduit, in the form of a simple and inexpensive metal-casting, is of Its longitudis exceptionally efiicient character. nal and transverse fins provide the desired amount of secondary heat-absorbing surface and such fins, together with the transverse channels 20, Hand, effectively direct, and control the flow of hot combustion-gases in a manner to enable a maximum amount of the heat of such gases to'be transferred to the water in the conduit. The strength of such conduit is such as to enable the casing of thetank heater to be.

readily supported thereon, the casing in effect being built around the conduit. As a result. the

use of the fastening devices and the like, heretofore used in mounting the usual coiled conduit in an enclosing casing, is wholly unnecessary. Moreover, by merely removingone or both of the jacket end caps, the longitudinal passages provided by the side wall fins may be readily cleaned by a'ram-rod type ofdevic'e, allas will be readily understood.

To those skilled in the art to which the presentinvention relates, further features and advantages of the invention will be evident from the foregoing description of one embodiment thereof. r

What I claim is: r '1. A tank heater water conduit, comprising a hollow body having a water inlet and a water outlet, a plurality of longitudinally disposed external fins on each side of said bodyand interrupted-to provide on each side of said body a 2 the gases remain in intimate contact with t e conduit side walls and the fins 2| thereof and a substantial amount of heat is absorbed from such gases by the water in the conduit as said gases travel through these intermediate fin passages.

Although the upper conduit channels 22 andv 23' (formed by interrupting the side wall fins 2| and I4) aid in effecting the desired travel of the side wall gases through the. passages 41 provided by the top side wall fins H, the primary function of these two upper channels is to direct inwardly into the top fin passages the gases travelling along the front and rear of the conduit. As there is little secondary heat-absorbing surfac .at the front and at the rear of the conduit t transversely disposed portion free of fins, and a pair of transversely disposed external fins on the front of said body and extending from opposite sides thereof .to at least the longitudinal center line of saidbody, there being one front fin above the front end of each of the aforesaid transversely disposed portions. 2. A tank heater water conduit. comprising a hollowbody having a water inlet and a water outlet,- a plurality of longitudinally disposed external gases which travel along these feel-l f paths.

reach the channels .22and 23 with a fair high temperature, even through their course of travel sets of front and rear fins I I and I8. By providing the channel 22 just below the right-hand upper front and rear fins l'lzand I8 and the channel 23 just below the left-hand upper front and rear fins l1 and I8, the gases travelling alone the front and rear of the conduit are caused to travel inwardly into such channels. from which they fiow upwardlythrough the passages "of of the heat thereof, as will be readily understood.

By having the top side wall fins. ll terminate below the top portion 15 of the conduit. as heretofore mentioned, the gases fiow .into the header or collecting chamber 35 with uniform velocity" or draft, notwithstanding the reduced and offset character of the, outlet from such chamber.

From the foregoing description thereof, it will .has been made somewhat tortuous by t e lower the top side wall fins 14. The result is the ex-' traction from these diverted hot gases of much fins on each side of said body and interrupted to provlde'on eachside of said body a transversely disposed'portion free of such fins, one of such transversely disposed portions being located at a lower level than the other, and a pair of trans-e versely disposed external fins on the front of said body and extending from opposite sides thereof toat least the longitudinal center line of said body, there being one front fin above the front end of eachof the aforesaid transversely disposed portions.

3. A tank heater water conduit, comprising a hollow body having a water inlet and 'a water outlet, a plurality of longitudinally disposed external 'fins on each side of said body and interrupted to provide on each side of said body a transversely disposed'portion free of fins, a pair of transversely disposed external fins on the front of said body, and a pair of transversely. disposed external fins on the back of said body, one of said front fins and one of said back fins being located just above the ends ofone of the aforesaid transversely disposed portions and the other front fin and the other back fin being located just above the ends of the other aforesaid transversely disposed portion.

4. A tank .heater water conduit, comprising a hollow body having a water inlet and a water.

outlet, a plurality of longitudinally disposed external fins on each side of said body and interrupted to provide on each side of said body a transversely disposed portion free of longitudinal fins, and other external iln means extending transversely of said body at the front thereof and located above'at least parts of the aforesaid transversely disposed side portions which are free of longitudinally disposed fins.

of said body at the front thereof, there being one such-transverselydisposed fin portion located in the region of each of the aforesaid transversely disposed side portions which is free of longitudinally disposed fins.

6. A tank heater water conduit, comprising a hollow body having a water inlet and a water outlet, a plurality of longitudinally disposed external fins on each side of said body and extending from substantially'the front of said body to substantially the rear thereof, the longitudinally disposed fins on each side of said body being interrupted to provide thereon a transversely disposed portion free of longitudinally disposed fins, and other external fin means extending transversely of said body at the front and at the back thereof and located above at least parts of the front and rear ends of the aforesaid transversely disposed side portions which are free of longitudinally disposed fins.

CLARENCE H. MORROW. 

